the Gape Colony Qnaggas. 317 



distinguislied from " Burcliell's Zebras," using tins term in its 

 broadest sense to include such diverse forms as Grant's, 

 Crawsliay's, Cluipman-'s, and the typical Burchell's, by tiie 

 presence on the skull in front of the orbit of a depression, 

 claimed to be the remains of a pit which in more archaic 

 forms lodged a facial gland. Evidence of the existence of 

 tliis depression in a quagga's skull was pointed out by 

 Dr. Forsyth Major in 1880. It is also present, as Mr. 

 Lydekker has sliown, in the skull of the animal in the 

 Britisli Museum. This conlirmation of Dr. Major's ob- 

 servation would, to a certain extent, justify a provisional 

 generalization as to its occurrence in all " true Quaggas' " 

 skulls, were it not that this pit belongs to the category 

 of characters which are likely to appear sporadically as 

 atavisms, and arc, therel'oro, from the systematic standi)oinf, 

 open to suspicion on the score of inconstancy. Sucli 

 characters are of doubtful value as a basis for the formation 

 of natural groups, for functionless vestiges have seldom 

 much im))ortance in taxonomy. This is the principal 

 argument to be alleged h priori against the belief in the 

 specific value of the depression in question. On h posteriori 

 grounds I also find reasons for rejecting that belief. 



Mr. Lydekker asserts that lie found no trace of the 

 depression in any of the Burcbell or Bonte, Qnaggas' skulls, 

 of which there are, he adds, a good number in the British 

 Museum. 1 cannot find in that institution any skull known 

 to be that of a tyi)ical Burehell. There are the skulls of 

 E. quogga Wahlbergi ; of two subspecitieally unknown 

 specimens received from the Zoological Society ; of two 

 labelled Crawshay's Quagga which were collected by Penrice 

 and are therefore probably referable to E. quagga Chapmanni; 

 and of three examples of Grant's Quagga, one ( ? ) obtained 

 by Gregory, and two ( c? ? ) by llinde on the Athi Plains. 

 Presunuibly, these are the skulls that Mr. Lydekker refers to 

 comprehensively as those of Bonte Qnaggas' ; but they 

 hardly justify the conclusion that the facial pit was absent in 

 the typical Burehell. They do, however, satisfy me that no 

 great reliance can be placed on the character under dis- 

 cussion ; for, although the skulls of the female Grant's 

 Quaggas have practically no trace of the depression, it is 

 very perceptible both to eye and touch in the skull uf the 

 stallion. it is certainly shallower than in the skull of 

 the type of Grey's Quagga, which is also, by the way, 

 that of a stallion ; but it is quite unmistakably present, and 

 supplies, so far as it goes, an almost exact mean between the 

 skull of Grey's Quagga, on the one hand, and the remaining 



